In the earlier article we have discussed different groups of minerals, like Mica, Amphibole,Pyroxene, Quartzgroup of minerals. This is another important group of minerals, which include a series of minerals that crystallize in the orthorhombic system. These minerals range in composition from ”forsterite” Mg2 SiO4. The composition of common Olivine is (Mg,Fe)2 SiO4.
Olivine (General)
Properties of Olivine: (Mg, Fe)2 SiO4
List of Contents
Crystal System: Olivines have an Orthorhombic crystal system.
Fracture: Olivines are found in Conchoidal fracture.
Hardness: Olivines have a hardness of 6.5-7 on Moh’s scale.
Olivine occurs mainly in the dark coloured igneous rocks such as gabbro, periodotite and basalt. The rock, dunite is made up almost wholly of olivine. Olivine alters very readity to serpentine.
Minerals of Olivine Species:
Dunite
Solid, grainy masses of Olivine. Usually classified as a rock.
Olivenoid
Extraterrestrial form of Olivine found in meteorites.
Peridote
Fe2Mg8O20Si5, Transparent green variety of Olivine that is used as a popular gemstone.
Calcio-olivine
Ca2SiO4
Fayalite
Fe2+2SiO4
Forsterite
Mg2SiO4
Glaucochroite
CaMn2+SiO4
Kirschsteinite
CaFe2+SiO4
Laihunite
(Fe2+0.5◻0.5)Fe3+[SiO4]
Larnite
Ca2SiO4
Liebenbergite
Ni2SiO4
Monticellite
CaMgSiO4
Tephroit
Mn2+2SiO4
Uses of Olivine Minerals:
Olivine is used in metallurgical process as a slag conditioner (A slag conditioner containing MgO, carbon or a filler and a binder is mixed and formed under pressure to produce aggregates which can have the form of a briquette. The slag conditioner is used to improve the operating performance and refractory life in steel melting furnaces).
Forsterite (a magnesium rich olivine) is added to blast furnaces to remove impurities from steel and to form a slag.
Olivine is used as refractory material, and casting sand, while making refractory bricks (ceramic bricks/ tiles). But usage of olivine as refractory material is not a cheap source, which is why it is gradually being replaced by other cheaper materials.
Olivine is resembles to ”peridote”, which is used in jewelry and has metaphysical importance. As peridote is expensive, therefore, Olivine is used as peridote substitutely.
Bricks made up of Olivine refractory material are used in construction of stoves and furnaces because of its high resistivity against heat and high temperatures.
Olivine refractory material is used in bricks to reduce the weathering caused by continuous heating and cooling of the walls of stoves.
Countries rich with Olivine Minerals:
Olivine is found abundantly in igneous rocks of following geographic regions;